Uric acid-lowering effect of harpagoside and its protective effect against hyperuricemia-induced renal injury in mice.

Hyperuricemia (HUA) is caused by increased synthesis and/or insufficient excretion of uric acid (UA). Long-lasting HUA may lead to a number of diseases including gout and kidney injury. Harpagoside (Harp) is a bioactive compound with potent anti-inflammatory activity from the roots of Scrophularia ningpoensis. Nevertheless, its potential effect on HUA was not reported. The anti-HUA and nephroprotective effects of Harp on HUA mice were assessed by biochemical and histological analysis. The proteins responsible for UA production and transportation were investigated to figure out its anti-HUA mechanism, while proteins related to NF-κB/NLRP3 pathway were evaluated to reveal its nephroprotective mechanism. The safety was evaluated by testing its effect on body weight and organ coefficients. The results showed that Harp significantly reduced the SUA level and protected the kidney against HUA-induced injury but had no negative effect on safety. Mechanistically, Harp significantly reduced UA production by acting as inhibitors of xanthine oxidase (XOD) and adenosine deaminase (ADA) and decreased UA excretion by acting as activators of ABCG2, OAT1 and inhibitors of GLUT9 and URAT1. Moreover, Harp markedly reduced infiltration of inflammatory cells and down-regulated expressions of TNF-α, NF-κB, NLRP3 and IL-1ß in the kidney. Harp was a promising anti-HUA agent.

Large-scale analysis of the N-terminal regulatory elements of the kinase domain in plant Receptor-like kinase family.

BACKGROUND: The N-terminal regulatory element (NRE) of Receptor-like kinases (RLKs), consisting of the juxtamembrane segment in receptor kinases (RKs) and the N-terminal extension segment in RLCKs, is a crucial component that regulates the activities of these proteins. However, the features and functions of the NRE have remained largely unexplored. Herein, we comprehensively analyze 510,233 NRE sequences in RLKs from 528 plant species, using information theory and data mining techniques to unravel their common characteristics and diversity. We also use recombinant RKs to investigate the function of the NRE in vitro. RESULTS: Our findings indicate that the majority of NRE segments are around 40-80 amino acids in length and feature a serine-rich region and a 14-amino-acid consensus sequence, 'FSYEELEKAT[D/N]NF[S/D]', which contains a characteristic α-helix and ST motif that connects to the core kinase domain. This conserved signature sequence is capable of suppressing FERONIA's kinase activity. A motif discovery algorithm identifies 29 motifs with highly conserved phosphorylation sites in RK and RLCK classes, especially the motif 'VGPWKpTGLpSGQLQKAFVTGVP' in LRR-VI-2 class. Phosphorylation of an NRE motif in an LRR-VI-2 member, MDIS1, modulates the auto-phosphorylation of its co-receptor, MIK1, indicating the potential role of NRE as a 'kinase switch' in RLK activation. Furthermore, the characterization of phosphorylatable NRE motifs improves the accuracy of predicting phosphorylatable sites. CONCLUSIONS: Our study provides a comprehensive dataset to investigate NRE segments from individual RLKs and enhances our understanding of the underlying mechanisms of RLK signal transduction and kinase activation processes in plant adaptation.

A Bioinformatic Analysis of Gut Microbiota Related with Immune Cell Infiltration in Colorectal Cancer.

OBJECTIVE: The composition of microbiota which correlates with infiltrating immune cells and clinical signatures is not clarified in CRC. METHODS: We applied 4 kinds of bioinformatic tools GSVA (version: 1.42.0), ESTIMATE (version: 1.0.13), CIBERSORT (version: 2.0), and immune-related genes. RESULTS: We found that a total of 8 types of microbiotas appeared in the three immune correlation analyses. Among these microbiotas, significant enrichments in relative abundances associated with immune cell infiltration can be found for the dominant phyla Proteobacteria, Firmicutes, and Actinobacteria. Moreover, there existed correlations between some of the 8 microbiotas and clinical-related indicators. CONCLUSION: We identified some novel microbiotas involved in immune regulation in CRC.

Morphology, genetic characterization and phylogeny of Moniliformis tupaia n. sp. (Acanthocephala: Moniliformidae) from the northern tree shrew Tupaia belangeri chinensis Anderson (Mammalia: Scandentia).

A new species of Moniliformis, M. tupaia n. sp. is described using integrated morphological methods (light and scanning electron microscopy) and molecular techniques (sequencing and analysing the nuclear 18S, ITS, 28S regions and mitochondrial cox1 and cox2 genes), based on specimens collected from the intestine of the northern tree shrew Tupaia belangeri chinensis Anderson (Scandentia: Tupaiidae) in China. Phylogenetic analyses show that M. tupaia n. sp. is a sister to M. moniliformis in the genus Moniliformis, and also challenge the systematic status of Nephridiacanthus major. Moniliformis tupaia n. sp. represents the third Moniliformis species reported from China.

CAR modulates plasma membrane nano-organization and immune signaling downstream of RALF1-FERONIA signaling pathway.

In Arabidopsis, the receptor-like kinase (RLK) FERONIA (FER) senses peptide ligands in the plasma membrane (PM), modulates plant growth and development, and integrates biotic and abiotic stress signaling for downstream adaptive responses. However, the molecular interplay of these diverse processes is largely unknown. Here, we show that FER, the receptor of Rapid Alkalinization Factor 1 (RALF1), physically interacts with C2 domain ABA-related (CAR) proteins to control the nano-organization of the PM. During this process, the RALF1-FER pathway upregulates CAR protein translation, and then more CAR proteins are recruited to the PM. This acts as a rapid feedforward loop that stabilizes the PM liquid-ordered phase. FER interacts with and phosphorylates CARs, thereby reducing their lipid-binding ability and breaking the feedback regulation at later time points. The formation of the flg22-induced FLS2-BAK1 immune complex, which depends on the integrity of FER-containing nanodomains, is impaired in fer and pentuple car14569 mutant. Together, we propose that the FER-CAR module controls the formation of PM nano-organization during RALF signaling through a self-contained amplifying loop including both positive and negative feedback.

Longitudinal study of patients with antimelanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease.

OBJECTIVES: To describe the 8-year longitudinal study and long-term prognosis of a large inception cohort of anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive (MDA5+) DM-interstitial lung disease (ILD) patients. METHODS: In total, 216 patients diagnosed with MDA5+ DM-ILD were enrolled and followed up to analyse long-term survival rate. Demographic and clinical variables were collected at baseline and each temporal end point. Seventy patients who survived the first year were analysed for the long-term serological and respiratory outcomes. RESULTS: A total of 85 patients (39.3%) died during the follow-up period up to 96 months, with 89% of the deaths occurring in the first year after diagnosis. Long-term outcome was reported in 70 patients. Serological markers including anti-MDA5 antibody showed significant improvement with time. Radiographic findings and pulmonary function also improved notably in the follow-up period, especially in rapidly progressive ILD group, as measured by high-resolution computed tomography imaging scores, the estimated forced vital capacity, estimated diffusing capacity of lung carbon monoxide and dyspnoea scores. Early application of anti-fibrosis therapy helped to improve long-term pulmonary function. CONCLUSIONS: MDA5+ DM-ILD patients had a high mortality rate despite aggressive treatment. Patients who survived the first year usually showed a significant improvement in serological markers and pulmonary function during the long-term follow-up.

Social Functioning Outcomes of a High School-Based Treatment Program for Adolescents with ADHD.

OBJECTIVE: We evaluated the extent to which receiving the multi-component treatment of the Challenging Horizons Program (CHP) would lead to significant improvements in social functioning, as well as in inattention, internalizing symptoms, parent stress, and emotion dysregulation for high-school-aged adolescents with attention-deficit hyperactivity disorder (ADHD). METHOD: Participants were 186 high-school-aged adolescents (74% White) with a diagnosis of ADHD who were randomly assigned to either CHP (n = 92; 80% boys; M age = 15.0; SD = 0.8) or Community Care (CC; n = 94; 78% boys; M age = 15.1; SD = 0.9) within each of 12 participating schools. Parent and adolescent reports of social functioning were the primary outcome measures. Secondary outcomes included ratings of symptoms of ADHD and related disorders, parent stress, and emotion regulation. RESULTS: Intent-to-treat analyses using hierarchical linear modeling revealed significant group-by-time interactions of medium magnitude (d range = .40 to .52) on parent-rated social skills. Significant group-by-time benefits were also identified for adolescent self-rated social skills as well as the secondary outcomes of parent-rated inattention symptoms, emotion regulation, and parenting stress. DISCUSSION: CHP appears to benefit social skills along with related characteristics for adolescents with ADHD. Understanding these unique findings for this population informs additional research related to treatment mechanisms and effectiveness trials.

Erk1/2 inactivation promotes a rapid redistribution of COP1 and degradation of COP1 substrates.

Anthrax lethal toxin (LT) is a protease virulence factor produced by Bacillus anthracis that is required for its pathogenicity. LT treatment causes a rapid degradation of c-Jun protein that follows inactivation of the MEK1/2-Erk1/2 signaling pathway. Here we identify COP1 as the ubiquitin E3 ligase that is essential for LT-induced c-Jun degradation. COP1 knockdown using siRNA prevents degradation of c-Jun, ETV4, and ETV5 in cells treated with either LT or the MEK1/2 inhibitor, U0126. Immunofluorescence staining reveals that COP1 preferentially localizes to the nuclear envelope, but it is released from the nuclear envelope into the nucleoplasm following Erk1/2 inactivation. At baseline, COP1 attaches to the nuclear envelope via interaction with translocated promoter region (TPR), a component of the nuclear pore complex. Disruption of this COP1-TPR interaction, through Erk1/2 inactivation or TPR knockdown, leads to rapid COP1 release from the nuclear envelope into the nucleoplasm where it degrades COP1 substrates. COP1-mediated degradation of c-Jun protein, combined with LT-mediated blockade of the JNK1/2 signaling pathway, inhibits cellular proliferation. This effect on proliferation is reversed by COP1 knockdown and ectopic expression of an LT-resistant MKK7-4 fusion protein. Taken together, this study reveals that the nuclear envelope acts as a reservoir, maintaining COP1 poised for action. Upon Erk1/2 inactivation, COP1 is rapidly released from the nuclear envelope, promoting the degradation of its nuclear substrates, including c-Jun, a critical transcription factor that promotes cellular proliferation. This regulation allows mammalian cells to respond rapidly to changes in extracellular cues and mediates pathogenic mechanisms in disease states.

Steatohepatitis Impairs T-cell-Directed Immunotherapies Against Liver Tumors in Mice.

BACKGROUND & AIMS: Nonalcoholic steatohepatitis causes loss of hepatic CD4+ T cells and promotes tumor growth. The liver is the most common site of distant metastases from a variety of malignancies, many of which respond to immunotherapy. We investigated the effects of steatohepatitis on the efficacy of immunotherapeutic agents against liver tumors in mice. METHODS: Steatohepatitis was induced by feeding C57BL/6NCrl or BALB/c AnNCr mice a methionine and choline-deficient diet or a choline-deficient l-amino acid-defined diet. Mice were given intrahepatic or subcutaneous injections of B16 melanoma and CT26 colon cancer cells, followed by intravenous injections of M30-RNA vaccine (M30) or intraperitoneal injections of an antibody against OX40 (aOX40) on days 3, 7, and 10 after injection of the tumor cells. We measured tumor growth and analyzed immune cells in tumor tissues by flow cytometry. Mice were given N-acetylcysteine to prevent loss of CD4+ T cells from liver. RESULTS: Administration of M30 and aOX40 inhibited growth of tumors from intrahepatic injections of B16 or CT26 cells in mice on regular diet. However, M30 and/or aOX40 did not slow growth of liver tumors from B16 or CT26 cells in mice with diet-induced steatohepatitis (methionine and choline-deficient diet or choline-deficient l-amino acid-defined diet). Steatohepatitis did not affect the ability of M30 to slow growth of subcutaneous B16 tumors. In mice with steatohepatitis given N-acetylcysteine, which prevents loss of CD4+ T cells, M30 and aOX40 were able slow growth of hepatic tumors. Flow cytometry analysis of liver tumors revealed reduced CD4+ T cells and effector memory cells in mice with vs without steatohepatitis. CONCLUSIONS: Steatohepatitis reduces the abilities of immunotherapeutic agents, such as M30 and aOX40, to inhibit tumor liver growth by reducing tumor infiltration by CD4+ T cells and effector memory cells. N-acetylcysteine restores T-cell numbers in tumors and increases the ability of M30 and aOX40 to slow tumor growth in mice.

Leflunomide versus azathioprine for maintenance therapy of lupus nephritis: a prospective, multicentre, randomised trial and long-term follow-up.

OBJECTIVES: Previous studies have compared mycophenolate mofetil and azathioprine as maintenance therapy for lupus nephritis (LN). Leflunomide is an immunosuppressant widely used in the treatment of rheumatoid arthritis. The aim of this investigator-initiated study was to compare the efficacy and safety of leflunomide versus azathioprine as maintenance therapy for LN. METHODS: 270 adult patients with biopsy-confirmed active LN from 7 Chinese Rheumatology Centres were enrolled. All patients received induction therapy with 6-9 months of intravenous cyclophosphamide plus glucocorticoids. Patients who achieved complete response (CR) or partial response (PR) were randomised to receive prednisone in combination with leflunomide or azathioprine as maintenance therapy for 36 months. The primary efficacy endpoint was the time to kidney flare. Secondary outcomes included clinical parameters, extrarenal flare and adverse effects. RESULTS: A total of 215 patients were randomly allocated to the leflunomide group (n=108) and azathioprine group (n=107). Kidney flares were observed in 17 (15.7%) leflunomide-treated patients and 19 (17.8%) azathioprine-treated patients. Time to kidney flare did not statistically differ (leflunomide: 16 months vs azathioprine: 14 months, p=0.676). 24-hour proteinuria, serum creatinine, serum albumin, serum C3 and serum C4 improved similarly. Extrarenal flare occurred in two patients from the azathioprine group and one patient from the leflunomide group. The incidence of adverse events was similar in the 2 groups: leflunomide 56.5% and azathioprine 58.9%. CONCLUSIONS: The efficacy and safety profile of leflunomide are non-inferior to azathioprine for maintenance therapy of LN. Leflunomide may provide a new candidate for maintenance therapy in patients with LN. TRIAL REGISTRATION NUMBER: NCT01172002.

Population genetic structure and connectivity of a riparian selfing herb Caulokaempferia coenobialis at a fine-scale geographic level in subtropical monsoon forest.

BACKGROUND: Rivers and streams facilitate movement of individuals and their genes across the landscape and are generally recognized as dispersal corridors for riparian plants. Nevertheless, some authors have reported directly contrasting results, which may be attributed to a complex mixture of factors, such as the mating system and dispersal mechanisms of propagules (seed and pollen), that make it difficult to predict the genetic diversity and population structure of riparian species. Here, we investigated a riparian self-fertilizing herb Caulokaempferia coenobialis, which does not use anemochory or zoochory for seed dispersal; such studies could contribute to an improved understanding of the effect of rivers or streams on population genetic diversity and structure in riparian plants. Using polymorphic ISSR and cpDNA loci, we studied the effect at a microgeographic scale of different stream systems (a linear stream, a dendritic stream, and complex transverse hydrological system) in subtropical monsoon forest on the genetic structure and connectivity of C. coenobialis populations across Dinghu Mountain (DH) and Nankun Mountain (NK). RESULTS: The results indicate that the most recent haplotypes (DH: H7, H8; NK: h6, h7, h11, h12) are not shared among local populations of C. coenobialis within each stream system. Furthermore, downstream local populations do not accumulate genetic diversity, whether in the linear streamside local populations across DH (H: 0.091 vs 0.136) or the dendritic streamside local populations across NK (H: 0.079 vs 0.112, 0.110). Our results show that the connectivity of local C. coenobialis populations across DH and NK can be attributed to historical gene flows, resulting in a lack of spatial genetic structure, despite self-fertilization. Selfing C. coenobialis can maintain high genetic diversity (H = 0.251; I = 0.382) through genetic differentiation (GST = 0.5915; FST = 0.663), which is intensified by local adaptation and neutral mutation and/or genetic drift in local populations at a microgeographic scale. CONCLUSION: We suggest that streams are not acting as corridors for dispersal of C. coenobialis, and conservation strategies for maintaining genetic diversity of selfing species should be focused on the protection of all habitat types, especially isolated fragments in ecosystem processes.

New paradigms in cell adaptation: decades of discoveries on the CrRLK1L receptor kinase signalling network.

Receptor-like kinases (RLKs), which constitute the largest receptor family in plants, are essential for perceiving and relaying information about various environmental stimuli. Tremendous progress has been made in the past few decades towards elucidating the mechanisms of action of several RLKs, with emerging paradigms pointing to their roles in cell adaptations. Among these paradigms, Catharanthus roseus receptor-like kinase 1-like (CrRLK1L) proteins and their rapid alkalinization factor (RALF) peptide ligands have attracted much interest. In particular, FERONIA (FER) is a CrRLK1L protein that participates in a wide array of physiological processes associated with RALF signalling, including cell growth and monitoring cell wall integrity, RNA and energy metabolism, and phytohormone and stress responses. Here, we analyse FER in the context of CrRLK1L members and their ligands in multiple species. The FER working model raises many questions about the role of CrRLK1L signalling networks during cell adaptation. For example, how do CrRLK1Ls recognize various RALF peptides from different organisms to initiate specific phosphorylation signal cascades? How do RALF-FER complexes achieve their specific, sometimes opposite, functions in different cell types? Here, we summarize recent major findings and highlight future perspectives in the field of CrRLK1L signalling networks.

Prognostic values of anti-Ro52 antibodies in anti-MDA5-positive clinically amyopathic dermatomyositis associated with interstitial lung disease.

OBJECTIVE: Anti-Ro52 antibody often co-occurs with anti-Jo1 antibody in antisynthetase syndrome and their co-occurrence correlates with a more aggressive clinical phenotype and poorer prognosis. The strong association of anti-Ro52 antibody with anti-melanoma differentiation-associated protein-5 (anti-MDA5) antibody has been indicated in juvenile myositis. The aim of this study was to assess the clinical significance of anti-Ro52 antibody in a cohort of adult patients with anti-MDA5-positive clinically amyopathic dermatomyositis with interstitial lung disease (CADM-ILD). METHODS: We assessed a cohort of 83 consecutive patients with anti-MDA5-positive CADM-ILD. Anti-MDA5 antibodies and anti-Ro52 antibodies were detected in immunoblotting and semi-quantitatively analysed by densitometry. Clinical features and the 24 month survival were compared between anti-MDA5-positive patients with and without anti-Ro52 antibodies. RESULTS: Anti-Ro52 antibodies were found in 74.7% of anti-MDA5-positive CADM-ILD patients and were associated with an increased frequency of rapidly progressive interstitial lung disease (RP-ILD; 54.8% vs 23.8%; P = 0.014) and cutaneous ulcerations (27.4% vs 4.8%; P = 0.033). The cumulative 24 month survival rate tended to be lower in patients with anti-Ro52 antibodies than patients without (59.9% vs 85.7%; P = 0.051). The combination of anti-Ro52 antibody status and anti-MDA5 antibody levels further stratified patients' survival rates, showing that the survival rate of patients who were dual positive for anti-MDA5 antibody and anti-Ro52 antibody was significantly lower than patients with mild positive anti-MDA5 antibody alone (59.9% vs 100%; P = 0.019). CONCLUSION: Anti-Ro52 antibody is highly prevalent in anti-MDA5-positive CADM-ILD patients and their coexistence correlates with a subgroup of patients with more aggressive phenotypes. The combination of anti-MDA5 antibody levels and anti-Ro52 antibody status could help to predict patients' prognosis and guide risk-based therapy.

First report of the prevalence and genetic characterization of Giardia duodenalis and Cryptosporidium spp. in Yunling cattle in Yunnan Province, southwestern China.

Yunling cattle is an unique cattle breed distributed in Yunnan Province, southwestern China. It is yet to know whether Yunling cattle are infected with Giardia duodenalis and Cryptosporidium spp.. The objectives of the present study were to investigate the prevalence and characterize the assemblages of G. duodenalis and species of Cryptosporidium spp. in Yunling cattle in Yunnan province. The overall prevalence of G. duodenalis and Cryptosporidium spp. were 10.49% (41/391) and 0.77% (3/391), respectively. The age was considered as the risk factor for Yunling cattle infection with G. duodenalis (χ2 = 8.082, OR = 2.56, P = 0.004). Two assemblages of G. duodenalis, assemblage A (n = 1) and assemblage E (n = 40), were identified by amplification of the ß-giardin (bg) and glutamate dehydrogenase (gdh) gene loci using the nested PCR methods. Furthermore, Cryptosporidium andersoni (n = 1) and Cryptosporidium ryanae (n = 2) were detected by nested PCR targeting the small subunit (SSU) rRNA gene. This is the first report of G. duodenalis and Cryptosporidium spp. in Yunling cattle in China, which provided baseline date for further studies of the prevalence, genetic identity, and public health potential of these parasites in Yunling cattle.

Urine Metabolic Fingerprints Encode Subtypes of Kidney Diseases.

Metabolic fingerprints of biofluids encode diverse diseases and particularly urine detection offers complete non-invasiveness for diagnostics of the future. Present urine detection affords unsatisfactory performance and requires advanced materials to extract molecular information, due to the limited biomarkers and high sample complexity. Herein, we report plasmonic polymer@Ag for laser desorption/ionization mass spectrometry (LDI-MS) and sparse-learning-based metabolic diagnosis of kidney diseases. Using only 1 µL of urine without enrichment or purification, polymer@Ag afforded urine metabolic fingerprints (UMFs) by LDI-MS in seconds. Analysis by sparse learning discriminated lupus nephritis from various other non-lupus nephropathies and controls. We combined UMFs with urine protein levels (UPLs) and constructed a new diagnostic model to characterize subtypes of kidney diseases. Our work guides urine-based diagnosis and leads to new personalized analytical tools for other diseases.

Targeting the crosstalk between cytokine-induced killer cells and myeloid-derived suppressor cells in hepatocellular carcinoma.

BACKGROUND & AIMS: Cytokine-induced killer (CIK) cell-based immunotherapy is effective as an adjuvant therapy in early stage hepatocellular carcinoma (HCC) but lacks efficacy in advanced HCC. We aimed to investigate immune suppressor mechanisms in HCC, focusing on the role of myeloid-derived suppressor cells (MDSCs) in response to CIK therapy. METHODS: MDSCs were quantified by flow cytometry and quantitative real-time PCR. Cytokines were detected by cytokine array. A lactate dehydrogenase cytotoxicity assay was performed in the presence or absence of MDSCs to study CIK function against HCC cells in vitro. An FDA-approved PDE5 inhibitor, tadalafil, was used to target MDSCs in vitro and in vivo. Two different murine HCC cell lines were tested in subcutaneous and orthotopic tumor models in C57BL/6 and BALB/c mice. The antitumor effects of human CIKs and MDSCs were also tested in vitro. RESULTS: Adoptive cell transfer of CIKs into tumor-bearing mice induced inflammatory mediators (e.g., CX3CL1, IL-13) in the tumor microenvironment and an increase of tumor-infiltrating MDSCs, leading to impaired antitumor activity in 2 different HCC models. MDSCs efficiently suppressed the cytotoxic activity of CIKs in vitro. In contrast, treatment with a PDE5 inhibitor reversed the MDSC suppressor function via ARG1 and iNOS blockade and systemic treatment with a PDE5 inhibitor prevented MDSC accumulation in the tumor microenvironment upon CIK cell therapy and increased its antitumor efficacy. Similar results were observed when human CIKs were tested in vitro in the presence of CD14+HLA-DR-/low MDSCs. Treatment of MDSCs with a PDE5 inhibitor suppressed MDSC suppressor function and enhanced CIK activity against human HCC cell lines in vitro. CONCLUSION: Our results suggest that targeting MDSCs is an efficient strategy to enhance the antitumor efficacy of CIKs for the treatment of patients with HCC. LAY SUMMARY: Cytokine-induced killer cells are a mixture of immune cells given to eliminate cancer cells. However, not all patients respond to this treatment. Herein, we show in 2 different liver cancer models that myeloid-derived suppressor cells are increased in response to cytokine-induced killer cell therapy. Targeting these myeloid-derived suppressor cells may provide an additional therapeutic benefit alongside cytokine-induced killer cell therapy.

Lupus-associated atypical memory B cells are mTORC1-hyperactivated and functionally dysregulated.

OBJECTIVES: A population of atypical memory B cells (AtMs) are greatly expanded in patients with active lupus, but their generation and pathophysiological roles are poorly defined. The aim of this study was to comprehensively characterise lupus AtMs with a purpose to identify therapeutic clues to target this B cell population in lupus. METHODS: Peripheral B cell subsets were measured by flow cytometry. Sorting-purified B cell subsets were subject to RNA sequencing and functional studies. Plasma cytokines and secreted immunoglobulins were detected by Luminex or ELISA. In situ renal B cells were detected by multiplexed immunohistochemistry. RESULTS: CD24-CD20hi AtMs were strongly increased in two Chinese cohorts of patients with treatment-naïve lupus. Gene expression profile indicated that B cell signalling and activation, lipid/saccharide metabolism and endocytosis pathways were abnormally upregulated in lupus AtMs. In addition, the mammalian target of rapamycin complex 1 (mTORC1) pathway was remarkably activated in lupus AtMs, and blocking mTORC1 signalling by rapamycin abolished the generation of T-bet+ B cells and terminal differentiation of lupus AtMs. Furthermore, lupus AtMs displayed a dysfunctional phenotype, underwent accelerated apoptosis, poorly co-stimulated T cells and produced proinflammatory cytokines. Interestingly, lupus AtMs were in a paradoxically differentiated status with markers pro and against terminal differentiation and enriched with antinucleosome reactivity. Finally, AtMs were accumulated in the kidneys of patients with lupus nephritis and associated with disease severity. CONCLUSIONS: These findings demonstrated that mTORC1-overactivated lupus AtMs are abnormally differentiated with metabolic and functional dysregulations. Inhibiting mTORC1 signalling might be an attractive option to target AtMs and to improve therapeutic effectiveness in patients with lupus.

Serum KL-6 level is a prognostic marker in patients with anti-MDA5 antibody-positive dermatomyositis associated with interstitial lung disease.

OBJECTIVE: This study aimed to investigate the clinical significance of Krebs von den Lungen-6 (KL-6) serum levels in patients with anti-MDA5 antibody-positive dermatomyositis (anti-MDA5+ DM) having interstitial lung disease (ILD), especially in the amyopathic DM phenotype. METHODS: The serum KL-6 level was measured using a chemiluminescence enzyme immunoassay (CLEIA) in patients with anti-MDA5+ DM, including clinically amyopathic dermatomyositis (CADM)-ILD and classic DM-ILD, and healthy donors. The baseline and post-treatment serum KL-6 levels were determined in 39 patients with CADM-ILD who experienced remission or acute exacerbation. The association between laboratory findings, high-resolution computed tomography (HRCT) scores, pulmonary function tests (PFTs), and the predictive value of baseline KL-6 level for death was analyzed. RESULTS: The serum KL-6 levels were significantly higher in patients with CADM-ILD (1339 ± 1329 U/mL) compared with DM-ILD (642.3 ± 498.4 U/mL) and healthy donors (162.4 ± 54.01 U/mL). The KL-6 levels correlated positively with chest HRCT scores, serum lactate dehydrogenase, serum ferritin levels, and PFTs, but not with erythrocyte sedimentation rate. During follow-up, the post-treatment serum KL-6 levels significantly reduced in the remission/stable group, but increased in the acute exacerbation group. Higher levels of ferritin and KL-6 and HRCT scores were independently associated with poor prognosis. The 1-year survival rate was significantly lower in patients with high KL-6 level than in those with low KL-6 level. CONCLUSION: The serum KL-6 levels may be a useful marker for predicting and monitoring ILD in Chinese patients with anti-MDA5+ DM, especially amyopathic DM phenotype.